The Division of Adolescent Medicine, Cook County Hospital is applying to become an Adolescent Medicine Trials Unit (AMTU) in the Adolescent Medicine Trials Network (ATN) being established by the National Institute of Child Health and Human Development. Adolescent Clinical Trials, Chicago, or ACT Chicago, will utilize the resources of the Division of Adolescent Medicine the CORE Center for HIV/AIDS and Infectious Diseases, and the myriad affiliated hospitals, medical centers, community organizations, and research bodies that refer to and cooperate with this model youth services center. As the largest single provider of comprehensive health services to youth ages 12-25 in Chicago, the Division operates a hospital based Adolescent/Youth Adult Clinic (AYAC) and a clinic for HIV(+) and affected youth at the CORE for HIV/AIDS and infectious diseases, and medically administers three high school-based health centers, all of which serve a population of youth who are at risk for acquiring STDs including HIV. The Division has successfully established itself as a model center for federal programs serving HIV infected youth. Chicago HIV Risk Reduction Partnership for Youth, CHRRPY, is a Special Project of National Significance operating since October of 1996. The Chicago of 1998. Project REACH (Reaching for Excellence in Adolescent Care and Health) has been a sub-unit of the Adolescent Medicine HIV/AIDS Research Network since of November, 1994. The Adolescent-Pediatric AIDS Clinical Trials Group (PACTG) began in February of 1999. The Division has extensive and very successful experience in identifying, recruiting, and retaining HIV infected youth and youth at risk in care and directing them into research, and in doing so, has innovated a variety of unique approaches. As a result, ACT Chicago will be prepared tp participate in all studies adopted by the Adolescent Medicine Trials Unit.